The present invention relates to an electrical connector for a flat conductor.
A Flexible Printed Circuit (FPC), a flat cable, and the likes are known as flat conductors. A connector disclosed in Patent Reference is known as an electrical connector that connects the flat conductor to a connection object member, for example, other circuit board.
Patent Reference: Japanese Patent Publication No. 11-031561
FIG. 6 is a perspective sectional view showing a conventional electrical connector. FIG. 7 is a partial perspective sectional view showing the conventional electrical connector.
In the connector disclosed in Patent Reference, as shown in FIGS. 6 and 7, a plurality of the terminals 51 is held in a housing 52 in a direction perpendicular to a plate surface thereof. The terminal 51 is made to maintain a plate surface of a metal sheet.
The terminal 51 has an approximate transverse H-shape. Further, each upper arm and lower arm of the terminal 51 is connected at a middle portion thereof in a longitudinal direction thereof. The upper arm elastically inclines and is displaceable as a lever with a connection portion thereof as a fulcrum. The upper arm is provided with a supporting arm 54A on a right side of a fulcrum portion 53.
Further, the upper arm is provided with a contact arm 54B having a contact portion 54C with a protrusion shape on a left side thereof. The lower arm is provided with a supporting arm 55A having a connection portion 55B on a distal end thereof on a right side of the fulcrum portion 53. Further, the lower arm is provided with a fixed arm 55D having a protrusion portion 55C on a left side.
The housing 52 is provided with grooves 56 corresponding to the terminals 51, so that the terminals 51 are inserted into the grooves 56. The terminals 51 can be inserted from a right side in FIG. 6. All of the grooves 56 communicate at a left opening 57 of the housing 52. Further, the grooves 56 communicate at a right opening 58 of the housing 52. A flat conductor is inserted between the contact arms 54B and the fixed arms 55D from the left opening 57. Further, the right opening portion 58 is provided with a pressing member 59 to be freely rotatable.
The pressing member 59 is made of an electrical insulation material similar to that of the housing 52. As shown in FIGS. 6 and 7, the pressing member 59 has an operation portion 59A, a rotation guided portion 59B, a pressing portion 59C that functions as a cam, and a shaft portion 59D.
The operation portion 59A protrudes from the right opening 58 of the housing 52 to be in a lever shape. The rotation guided portion 59B has a section having a circular arc shape and is rotated to guide in a recessed portion. The recessed portion is provided to correspond to the supporting arm 55A of the lower arm of the terminal 51. When the pressing member 59 is rotated to be at a close position in a clockwise direction in the operation portion 59A, the pressing portion 59C presses the supporting arm 54A of the upper arm of the terminal 51 upwardly.
The shaft portion 59D is provided to protrude from both ends of a width direction of the pressing member 59. The shaft portion 59D has a pivot on an extension of a centerline of the circular arc of the rotation guided portion 59B. The shaft portion 59D is supported to be movable and guided along with the rotation guided portion 59B when the pressing member 59 is rotated.
A taper groove portion 61 and a step groove portion 62 are provided inside of a sidewall 60 of the housing. The taper groove portion 61 and the step groove portion 62 are adjacent to each other. Further, a slit 64 is provided in each border portion of the sidewalls 60 and a top wall 63 of the housing. The slit 64 enables the sidewall 60 to elastically bend outwardly. The pressing member 59 is incorporated into the housing 52 from a right side in FIG. 6 and from an upper right side in FIG. 7.
At that time, the shaft portion 59D elastically deforms to bend the sidewall 60 outwardly to be accommodated in the step groove portion 62 while moving the taper groove portion 61 of the sidewall 60. When the shaft portion 59D is accommodated in the step groove portion 62, the elastic deformation to bend is released. Accordingly, the shaft portion 59D engages with the step groove portion 62 and becomes hard to disengage upon receiving an external force.
As described above, in the connector disclosed in Patent Reference, the shaft portion provided on both side edges of the pressing member engages with the step groove portion of the housing in an arrangement direction of the terminals, so that the pressing member does not come off.
When the number of the terminals increases, a width dimension between both side edges of the pressing member increases and becomes easier to bend. In a range between the both side edges, the recessed portion provided in the supporting arm of the terminal prevents the pressing member from coming off to some extent.
However, when the pressing member is bent as described above due to an external force, the rotation guided portion of the pressing member easily protrudes from the recessed portion. Accordingly, solely the shaft portion has to be depended on to prevent the pressing member from coming off. As a result, the shaft portion may be overloaded; an engagement depth with the step groove portion of the shaft portion may become small due to the bend described above; or the sidewall may open due to a large force from the shaft portion, thereby further decreasing the engagement depth.
When one of the situations described above occurs, the shaft portion may break or the pressing member may come off. That is, when the pressing member is opened and closed, or when an inadvertent external force is applied to the pressing member, the pressing member may come off. Accordingly, the flat conductor can lose contact with the terminal; and therefore, a function as the connector can be lost.
In view of the problems described above, an object of the present invention is to provide an electrical connector for a flat conductor, in which it is possible surely prevent a pressing member from coming off without enlarging a size of the electrical connector. Another object of the present invention is to provide an electrical connector that prevents a pressing member from coming off even though the number of terminals increases.
Further objects and advantages of the invention will be apparent from the following description of the invention.